Since the
advent of clear label sensors in the 1990s, several different
label sensor technologies have emerged  optical sensors,
ultrasonic sensors and two types of capacitive sensors.

Test results from Lion Precision, who provides label sensors
using all these technologies, show distinct differences in regard
to registration accuracy. There are several advantages
and disadvantages to each technology, according to Mark
Kretschmar, communication manager for Lion Precision. The
typical end-user or machine designer doesnt have the time
or inclination to search out the differences for such a small
piece of the labeling system, but the differences can matter,
especially at higher speeds. As the leading clear label sensor
provider, we felt compelled to discover and share the accuracies
of each of our technologies.

Lion Precision
designed and built a machine that uses a rotary encoder and a
gear belt to precisely control and measure the location of label
edges on a loop of ordinary paper labels. The system is capable
of measuring label edge position with better than one micron
of accuracy. Sensors using each of the four technologies were
tested on the device with web speeds of 70 meters/minute and
220 meters/minute and compared. The results were very clear,
said Kretschmar. The capacitive technology registered no
errors, even at 220 meters-per-minute. Optical sensors
showed a small decrease in accuracy at the higher speed. Ultrasonic
sensors, while having the advantage of working with a very wide
range of label materials, showed considerably larger errors and
a clear relationship between web speed and registration accuracy.
Kretschmar cautions, Registration accuracy is not the only
factor in making a label sensor choice. Each technology can struggle
with certain types of label and liner materials and have different
setup procedures. If registration accuracy is of paramount
importance, ultrasonic sensors are not the best choice, especially
at higher speeds. If using slower speeds and the primary concern
is usability on the widest range of materials, ultrasonic may
be a good choice.

Lion Precisions
newest label sensor, the LRD8200 uses ultrasonic technology.
It isnt always about having the latest gadget or
technology, according to company president, Don Martin.
For users concerned with registration accuracy at high
speeds, we steer them toward the capacitive sensors because they
will get better results, even though they arent the newest
product.

Detailed results
of the test are available as a web page or PDF at www.labelsensors.com, a new site dedicated
to helping users make the best sensor choice.

In 1958, Lion Precision
was the first company to provide capacitive displacement sensors
to industry. The company has expanded its product offering to
include eddy-current displacement sensors and some application
specific sensors for the machine tool, packaging and PCB industries.
The company is focused on assisting users in sensor implementation
by providing expert guidance and optimized systems including
custom designs.Lion Precision, an IBS
Precision Engineering partner, sells the Triskelion in the United
States. The company was established in 1958 and pioneered commercially
available noncontact sensing systems. The company provides high-performance
capacitive and eddy-current displacement sensors for industries
such as machine tool, semiconductor, disk drive, automotive,
packaging, and university and national laboratory research.December 2012